PROJECT SUMMARY Asthma morbidity is a major public health problem among low-income minority children living in urban neighborhoods, and contributors to asthma disparities may include home environmental exposures to biotic material. While allergens and endotoxin have been studied extensively, less is known about the role of bacterial and fungal communities, about the upstream influence of environmental microbiota on airway microbiota, and about the downstream contributions of airway microbiota to asthma morbidity. Therefore, we will take advantage of a natural experiment to understand whether changes in microbiota occur in children who move from high-poverty, urban neighborhoods to low-poverty neighborhoods, primarily in the suburbs, through the Baltimore Housing Mobility Program (BHMP), the nation's largest mobility program. We will leverage existing support for a prospective cohort study of children with asthma and their families enrolled through BHMP to evaluate the hypothesis that moving to a low-poverty neighborhood through a housing mobility program will result in changes in home microbial exposures (bacterial and fungal communities). We further hypothesize that changes in the microbial composition and diversity of home exposures will be linked to alterations in microbial composition of the child's airway and improvements in asthma, controlling for changes in other biotic pollutants. Through prospectively evaluating 5-17 year old children with persistent asthma and their home environments before and after they and their families move with the support of BHMP, we seek to address the following specific aims: 1) To assess the effects of moving from a high-poverty urban neighborhood to a low-poverty suburban neighborhood on home and child airway microbiota, and 2) To explore the influence of changes in home dust and child airway microbiota on asthma outcomes. The proposed study's findings will provide new insights into environmental causes of asthma disparities and greater understanding of how changes in home environmental and child airway microbiota may influence asthma morbidity among low-income children.